The present invention relates generally to surgical instruments and more specifically to surgical clip appliers used for applying ligating clips to blood vessels and other tubular ducts or tissue.
In surgical procedures, it is frequently necessary to ligate ducts, such as blood vessels, or other severed tissue. For this purpose, it is well-known to use surgical clip appliers, such as that described in U.S. Pat. No. 3,439,522, to apply surgical clips to a duct or tissue to be ligated. Such clip appliers typically have a scissor-like construction, with a pair of movable handles which are grasped by the surgeon, and a pair of movable jaws opposite the handles into which a surgical clip is placed. Such clips usually have a pair of connected legs to form a U or V shape. When the handles are closed, the jaws close the legs of the clip together on the vessel or other tissue to be ligated.
In some surgical procedures, it is desirable to use a clip applier which is configured to allow tissue ligation in inaccessible areas of the surgical site. To address this need, a number of surgical clip appliers have been developed with the jaws extended from the handles at a distance, or with the jaws oriented at various angles. Examples are described in U.S. Pat. Nos. 3,777,538, and 4,440,170.
Other known clip appliers, such as that described in U.S. Pat. No. 4,616,650, provide for retaining multiple clips in the applier and feeding the clips toward the distal end of the applier, thereby permitting the surgeon to apply multiple clips at various places in the surgical site without removing the clip applier from the site to place another clip in the jaws. In some of these known devices, the clip applier is designed to accommodate an interchangeable cartridge containing multiple clips. An example is seen in U.S. Pat. No. 3,675,688.
In some surgical procedures, however, known clip appliers suffer certain drawbacks. Known clip appliers pose a potentially serious risk of injury to patients in the event the closure mechanism, be it a pair of jaws or a hammer and anvil, is closed when a clip is not present therein. When the closure mechanism is closed without a clip present, known clip appliers frequently permit the clip-closing surfaces to move into contacting or overlapping engagement with one another, which in many cases will cut, sever or otherwise damage any tissue lying in the closure mechanism. Clip appliers capable of storing multiple clips for sequential application frequently provide no indication to the user when all of the clips have been applied. Moreover, known clip appliers generally do not prevent the user from attempting to apply a clip by positioning the closure mechanism over a portion of tissue and closing on the tissue even though no clips remain in the device. The problem is worsened by the often poor visibility in the body cavity preventing clear visualization of the closure mechanisms and the presence of a clip therein. In addition, even if the user recognizes that no clips remain in the device, body tissue may remain positioned within the closure mechanism, potentially interfering with removal of the clip applier or injuring the patient if removal is attempted.
For these reasons, it would be desirable to provide an improved surgical clip applier which eliminates the risk of tissue damage when all of the clips in the applier have been applied. Preferably, the apparatus will provide an indication to the user that all clips have been applied, as well as prevent the user from actuating the clip closure mechanism. More desirably, the apparatus will serve to remove any tissue positioned between the jaws after all clips in the applier have been applied so as to disengage the applier from such tissue, allowing the applier to be removed from the surgical site without interference. The apparatus should be adaptable to various types of clip appliers having a variety of clip feeding and closure mechanisms.